Diseases of the Respiratory System 155 



pears to be a contagious germ disease as it often affects a 

 large number of birds kept together. 



Quite possibly this is not a separate disease but is either 

 a severe form of cold occurring in many individuals of a 

 flock which has been exposed to unfavorable, unsanitary 

 conditions, or is a mild form of roup. Affected birds should 

 be isolated. If diarrhea is present give one-half to one tea- 

 spoonful of Epsom salts dissolved in water. Treatment the 

 same as for colds. 



Prognosis. — Most cases recover in a week or ten days. 

 Severe cases die in a day or two or sometimes within a few 

 hours after the appearance of the first symptoms. 



Roiiy 



Veterinarians have distinguished two diseases belonging 

 to this general class of troubles as follows : (a) roup or 

 contagious catarrh when only catarrhal symptoms are 

 present, and (6) diphtheria, diphtheritic roup and canker when 

 diphtherial patches and false membranes are formed. The 

 bacteriologists Harrison and Streit,^ consider these different 

 stages of the same disease. This view has been quite 

 generally accepted. Cary ^ and several other workers ^ not 

 only consider these as one disease but also believe that sore- 

 head, chicken pox or epithelioma contagiosmn is also a form 

 of this disease. Evidence for the identity of " avian 

 diphtheria " or " diphtheritic roup " and chicken pox is 



'Harrison, F. C, and Streit, H., "Roup." Ontario Agr. Col. 

 and Expt. Farm Bull. 125. 1902. Ihid., Bui. 132. 1904. 



^ Gary, C. A., " Chicken Pox or Sore Head in Poultry." Ala- 

 bama Col. Sta. Bui. 136. 1906. 



^For example, Kingsley, A. F., "Epithelioma Contagiosum." 

 Amer. Vet. Rev., 30. 1907. Hadley, F. B., and Beach, B. A., 

 "Controlling Chicken Pox, Sore Head or Contagious Epithelioma 

 by Vaccination." Proc. Amer. Vet. Med. Assoc, Vol. 50, pp. 704- 

 712. 1913. 



